Nano-sized γ-alumina (γ-Al2O3) was first prepared by a precipitation method. Then, active component of cobalt and a series of alkaline- earth metal promoters or nickel (Ni) with different contents were loaded on the...Nano-sized γ-alumina (γ-Al2O3) was first prepared by a precipitation method. Then, active component of cobalt and a series of alkaline- earth metal promoters or nickel (Ni) with different contents were loaded on the γ-Al2O3 support. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD) and thermogravimetry analysis (TGA). The activity and selectivity of the catalysts in catalytic partial oxidation (CPO) of methane have been compared with Co/γ-Al2O3, and it is found that the catalytic activity, selectivity, and stability are enhanced by the addition of alkaline-earth metals and nickel. The optimal loadings of strontium (Sr) and Ni were 6 and 4 wt%, respectively. This finding will be helpful in designing the trimetallic Co-Ni-Sr/γ-Al2O3 catalysts with high performance in CPO of methane.展开更多
This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature...This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature inversion occurred primarily near the salinity front, with an average temperature difference(ΔT) of 0.42°C between the inversion layer and the underlying water. The inversion layer was approximately 4 m thick on average, with an upper boundary at a depth of 1–6 m and a lower boundary at a depth of 3–10 m. Different mechanisms and dynamic processes were responsible for temperature inversion in different parts of the study area.(1) At the salinity front in the west of the ZRE, the measurements collected by CTD(conductivity,temperature, and depth) showed that the low-salinity water mass on the inner side of the front was approximately2°C cooler than the high-salinity water mass on the outer side. Temperature inversion occurred when the cooler low-salinity water overlapped the warmer high-salinity water near the front due to the driving force of the background flow.(2) Inversion layers occurred at the mouth of the Taiping waterway as a result of varying horizontal flow between two different water masses under the effects of tides and runoff.(3) To the southwest of Hong Kong, temperature inversion occurred due to the interaction of upwelling and the salinity front.展开更多
基金supported by the Open Foundation of State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University (No.200906)the Natural Science Foundation of Jiangxi Province (No.2010GZH0048)+1 种基金the National Natural Science Foundation of China (No. 21067004)the Young Science Foundation of Jiangxi Province Education Office (No. GJJ10150)
文摘Nano-sized γ-alumina (γ-Al2O3) was first prepared by a precipitation method. Then, active component of cobalt and a series of alkaline- earth metal promoters or nickel (Ni) with different contents were loaded on the γ-Al2O3 support. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD) and thermogravimetry analysis (TGA). The activity and selectivity of the catalysts in catalytic partial oxidation (CPO) of methane have been compared with Co/γ-Al2O3, and it is found that the catalytic activity, selectivity, and stability are enhanced by the addition of alkaline-earth metals and nickel. The optimal loadings of strontium (Sr) and Ni were 6 and 4 wt%, respectively. This finding will be helpful in designing the trimetallic Co-Ni-Sr/γ-Al2O3 catalysts with high performance in CPO of methane.
基金The National Basic Research Program of China under contract No.2015CB954004the National Natural Science Foundation of China under contract Nos 41776027,41606009 and U1405233
文摘This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature inversion occurred primarily near the salinity front, with an average temperature difference(ΔT) of 0.42°C between the inversion layer and the underlying water. The inversion layer was approximately 4 m thick on average, with an upper boundary at a depth of 1–6 m and a lower boundary at a depth of 3–10 m. Different mechanisms and dynamic processes were responsible for temperature inversion in different parts of the study area.(1) At the salinity front in the west of the ZRE, the measurements collected by CTD(conductivity,temperature, and depth) showed that the low-salinity water mass on the inner side of the front was approximately2°C cooler than the high-salinity water mass on the outer side. Temperature inversion occurred when the cooler low-salinity water overlapped the warmer high-salinity water near the front due to the driving force of the background flow.(2) Inversion layers occurred at the mouth of the Taiping waterway as a result of varying horizontal flow between two different water masses under the effects of tides and runoff.(3) To the southwest of Hong Kong, temperature inversion occurred due to the interaction of upwelling and the salinity front.
